I have recently done a small investigation into improving the insulation of my windows. They are all single glazed, in timber frames, and some are sash windows. I looked at Community Energy Action’s plastic film product, and The Energy Savings Centre’s Acrylic Secondary Glazing.

The acrylic secondary glazing fits a sheet of acrylic over existing windows, using magnetic strips on the existing frame. They claim it will improve UV penetration, condensation, noise pollution, draughts and insulation. It is not visible from the outside, and can be colour matched to the existing frames. The magnetic strips allow a small amount of movement which is normal in timber framed buildings. The quote seemed very reasonable, and significantly cheaper than double glazing! I’m hoping to install at least one window before the winter (dependant on the landlord!)

The plastic film product is a cross between food wrap and cellophane. You attach it to the frame using double sided tape, then shrink the wrinkles using a hair dryer. This has a similar list of benefits to the secondary glazing, but will not last indefinitely. I fitted it to half of my bedroom window, and saw the following improvement in condensation in the morning! (The left half has the film, the right half does not.)

I haven’t managed to find a sensible solution to my draughty sash windows yet though, both suppliers recommended fitting over the whole window opening but this would mean they couldn’t be opened, and I think the plastic film would get caught on the blinds. I’m planning on draught stopping them as much as possible, and thermally lining the blinds. Here’s to a warmer winter!